Apparatus for polishing articles



Jan. 7, 1964 P. MIDREILING 3,116,572

APPARATUS FOR POLISHING ARTICLES Filed June so, 1959 e Sheets-Sheet 1 01 tom e s Q8 Q3 ms Q wa E g 3 Q I Q h 15 a Q g vmsms .0 \Q Q MN QR \Q N A Q m 6V h a o m 8v w wk 8 .1 o @w E m. .8. m k km 3% vm 3 A. m. A NW 8. H g N A 38 Q m m Q 2 v N P. M. DREILING APPARATUS FOR POLISHING ARTICLES Jan. 7, 1964 Filed June :so, 1959 6 Sheets-Sheet 2 mm mm R M D a M m R E d W Jan. 1964 P. M. DREILING APPARATUS FOR POLISHING ARTICLES 6 Sheets-Sheet 3 Filed June 30, 1959 k Mi Jan. 7, 1964 p, DRE|L|NG 3,116,572

APPARATUS FOR POLISHING ARTICLES Filed June 50, 1959 6 Sheets-Sheet 4 FIG. II.

FIG. I0.

70 INVENTOR. PETER M. DREILgC? BY 4 K Jan. 7, 1964 APPARATUS FOR POLISHING ARTICLES Filed June 30, 1959 P. M. DREILING 6 Sheets-Sheet 5 vl'iforneys I United States Patent 3,116,572 APPARATUS FOR POLISHING ARTICLES Peter M. Dreiling, Sheboygan, Wis, assignor to Iii-Lite Polishing Machine Company, Inc, Shehoygan, Wis, a corporation of Wisconsin Filed June 30, 1959, Ser. No. 823,878 14 Claims. (Cl. 51-67) This invention relates to an apparatus for polishing an article and more particularly to the polishing of a workpiece having a bottom surface and side walls.

The present apparatus is designed to polish or otherwise finish a workpiece having a bottom surface and side walls in a continuous operation. The apparatus includes a chuck which supports the workpiece and is mounted for rotation on a main frame member. A pair of heads, each of which carries an abrasive contact member, such as a belt, are supported on a turret which is adapted to pivot toward the chuck to bring the heads into polishing position, or alternately, pivot away from the chuck to permit insertion and withdrawal of the workpiece from the chuck.

One of the heads is adapted to engage the bot-torn surface of the workpiece and reciprocate from the center of the workpiece outwardly to the periphery while the workpiece is rotated by the chuck to polish the bottom surface. The second head is adaptal to move from the outer periphery of the side wall of the workpiece to the bottom surface and return to polish the side wall. The.

abrasive members carried by the heads are independently biased into contact with the respective surfaces of the workpiece by an air pressure mechanism which provides a floating action for the abrasive members. This floating action compensates for out-of-roundness or deformities in the contour of the side walls or bottom surface and in addition, permits the abrasive members to travel over embossments or ribs formed in the surfaces of the workpiece.

The apparatus is particularly adaptable for use with stationary abrasive members or belts which will provide a sunray-type of finish for the workpiece. The apparatus includes a provision for automatically indexing the stationary belts on the completion of the stroke of travel of the heads so that a new section of the belt will be in position for polishing on the successive strokes.

In addition, both of the stationary abrasive belts are positioned so that the rotation of the workpiece is in the same direction as the longitudinal edges of the belt. This provides a superior finish for the workpiece.

The invention also includes a provision for slowing down the side wall polishing head at any given position in its stroke of travel to permit the abrasive member to conwntrate on bad areas in the side wall surfaces. This slow down feature is accomplished by means of a hydraulic cam mechanism which is automatically actuated by the travel of the side wall head to permit the abrasive member to dwell in a given area and provide an increased polishing action.

In addition, the polishing operation adorded by the present invention is completely automatic and any one of a number of preset automatic cycles can be employed to provide any desired sequence of polishing operations. Furthermore, by using a timer in the electrical system, the sequence of operations can be repeated without the turret opening.

The present invention provides an apparatus that can be readily set up for different production runs or polishing operations on various size workpieces with a minimum of tooling cost. The apparatus automatically compensate-s for irregularities or deformities .in the surface of the workpiece and each of the abrasive members can ice be regulated independently so that the pressure of the abrasive member against the wall can be changed, as desired, and the speed of each abrasive member along the wall can be similarly adjusted.

Other objects and advantages will appear in the course of the following description.

The drawings illustrate the best mode presently contemplated of carrying out the invention.

In the drawings:

FEGURE l is a perspective view of the apparatus of the invention with parts broken away;

FIG. 2 is a side elevation of the apparatus;

FIG. 3 is an end elevation of the apparatus;

FIG. 4 is a sectional view taken along line 4--4 of FIG. 2;

FIG. 5 is a view taken along line 5-5 of FIG. 2;

FIG. 6 is a view taken along line 6--6 of FIG. 2;

PEG. 7 is a diagrammatic representation of the electrical system;

FIG. 8 is a view taken along line 83 of FIG. 3;

FIG. 9 is an enlarged rlragmentary horizontal section with parts broken away showing the construction of the block which provides pivotal movement for the support plate;

FIG. 10 is a view taken along line 1010 of FIG. 5; and

FIG. 11 is a longitudinal section of the thread stocks and actuating nuts for the control system of the side wall polishing head. V

The drawings illustrate an apparatus for polishing, grinding or abrading a workpiece in a continuous operation. The apparatus comprises a main frame 1 which supports the chuck assembly 2 on which the workpiece 3 is mounted. A turret is pivotally connected about a vertical axis to frame 1 and carries a pair of polishing heads which are adapted to engage the side walls and bottom walls, respectively, of the workpiece to polish the same when the turret is swung to the closed position.

The chuck assembly 2 includes a chuck 5 which has a shape generally corresponding to the workpiece 3 and is bolted to a chuck support plate 6. As shown in the drawings, the workpiece 3 is a pan or pot having a substantial depth and having side walls which are disposed generally normal to the bottom surface. However, it is contemplated that any desired shape of workpiece can be polished by the apparatus of the invention.

The chuck support plate 6 is secured to a hollow shaft 7 which is journaled in a bearing assembly 8 secured to the main frame 1. The shaft 7 is driven by a suitable hydraulic motor 9 to thereby rotate the chuck and the workpiece about the axis of the shaft 7. The workpiece is held tightly against the chuck by a conventional vacuum system in which a vacuum is drawn through the interior of the hollow shaft 7 to hold the workpiece tightly against the inner surface of the chuck 5 during the polishing operation.

The chuck assembly 2 is fixed with respect to the main frame 1 except for the rotation of the shaft 7, while the polishing heads carriedby turret 4 are adapted to move with respect to the chuck to polish the workpiece.

The turret 4 includes a generally L-shaped column 10 which is pivotally connected to a vertical shaft 11 journaled within mounting brackets 12 attached to main frame 1. The side wall polishing head 13 and the bottom wall polishing head 14 are secured to the column 19 and are adapted to move in a horizontal plane as the column 10 is pivoted about the vertical shaft 11.

The column 16 is pivoted with respect to the shaft 11 by an air cylinder 15 having one end connected to the main frame 1. The piston rod 16 of the cylinder 15 is piyotaily connected to a lug 17 attached to the column 13. Air is introduced into the ends of the cylinder 15 through lines 18 and 19 and, as air is introduced through line 18, the piston rod 16 is retracted to pivot the column 10 and heads 13 and 14 away from the frame 1 and thereby permit the insertion and removal of the workpiece from within the chuck 5. By introducing air into the opposite end of the cylinder through line 19, the column 10 and heads 13 and 14 are pivoted toward the frame 1 and chuck to bring the heads in position for the polishing operation.

The mounting bracket 12 includes an arm 20, as best shown in FIG. 6, which carries an adjustable stop 21 and limit switch 22 which are adapted to be engaged by the forward wall 23 of column when the turret is in the closed position. By adjustment of stop 21, the position of the heads 13 and 14 with respect to the workpiece can be varied.

The side wall polishing head 13 comprises, in general, a support member 24 which is connected to column 10 and supports a slide 25 and belt frame 26. The belt frame carries an abrasive belt 27 or other abrasive member adapted to luggage and polish the side wall of the workpiece.

The support member 24 is slidably connected to the column 10 to provide a vertical adjustment for the abrasive member 27 in order to accommodate workpieces of various diameter. The slidable connection is accomplished by means of a threaded shaft 28 which extends through an opening in the top surface of column 19 and is threaded into a block 29. The side wall 36 of column 10 is provided with a vertical slot 31 which extends the length of the side wall, and the block is provided with a threaded neck 32 which projects within the slot 31 and through an opening in member 24. The end of neck 32 is threadedly engaged by a nut 33.

The neck 32 of block 29 is adapted to slide within the slot 31 as the shaft 28 is rotated to thereby raise or lower the support member 24.

With this construction, the position of support plate 24 can be manually adjusted by turning shaft 28 to thereby vary the vertical position of the abrasive member 27 carried by side wall head 13 with relation to the chuck 5. This permits the apparatus to be employed for pots or workpieces having various internal diameters, for the support member 24, which carries the abrasive member' 27, can be readily adjusted in a vertical direction to accommodate workpieces of various diameter.

A provision is also made to permit the support member 24 and the abrasive member 27 carried thereby to be pivoted in a vertical plane with respect to column 10 to accommodate various angles of the side wall of the workpiece. To accomplish the pivotal action, a slot is provided in the support plate 24 and the threaded neck of block 36, similar to block 29, extends through the slot 35 in support plate 24, through the slot 31 in column 1%) and is threadedly engaged with a nut 37. By loosening the nuts 33 and 37, the entire support plate 24 can be pivoted in a vertical plane with respect to column 16 to provide a degree of tilt for the support plate to accommodate side walls of various angularity. The slot 35 permits the support plate 24 to be pivoted with respect to column 10.

The block 36 is provided with a horizontal, threaded opening and a rod 38 is threaded within the opening and extends the length of the support member 24. The outer end of the rod 38 is connected to a plate 39 secured to the end of member 24.

To slidably mount slide 25 on support plate 24, the slide is provided with a way 49 which receives the guides 41 on support plate 24. Adjustable gibs 41a are provided between the sliding surfaces to take up the wear of the sliding motion. The slide 25 is also provided with a curved recess or notch 42 which complements the notch 43 in the support plate 24.

To move the slide with respect to the support plate, a piston rod 44 of cylinder 45 is connected to the forward end of the slide 25 by a plate 46. A threaded rod 47 is connected to the rear end of the cylinder by a clevis 48 and extends outwardly through the stop plate 3? connected to support plate 24 and is secured by suitable lock nuts. Hydraulic fluid is introduced into the opposite ends of the cylinder through lines 49 and 50, respectively. The adjustment provided by threaded rod 47 is employed to vary the longitudinal position of cylinder and thereby vary the inward position of the stroke of the abrasive member 27.

By introducing hydraulic fluid through line 49 into the cylinder 45, the piston rod will be extended to move the slide 25 and the abrasive member 27 toward the chuck 5. Conversely, by introducing hydraulic fluid through line 50, the piston rod will be withdrawn into the cylinder to move the slide away from the chuck.

The belt frame 26 is pivotally connected to the slide 25 and serves to support and guide the abrasive belt 27 toward the workpiece. The belt frame 26 is pivotally secured to the slide by means of a shoulder bolt 52 which is journaled within a boss 53 formed on the frame 26 and is threaded into a suitable opening in the slide 25. The belt frame 26 is provided with an arm 54 which extends outwardly toward the chuck and carries a tip 55. The tip 55 is provided with a pair of belt guides 56 and 57 which straddle a rubber nose 58 secured centrally on the tip 55. As best shown in FIG. 1, the belt 27 approaching the tip 55 is turned under the guide 56, then passes over rubber nose 58 and then is again twisted under the belt guide 57. This results in the side edges of the abrasive belt 27 being disposed generally parallel to the direction of rotation of the side walls of the workpiece. As the side edges of the belt are disposed parallel to the direction of rotation, lateral displacement of the belt on the nose 58 will be prevented, resulting in an improved appearance.

The belt 27 is moved inwardly and outwardly along the side wall of the workpiece by means of the cylinder 45 which moves the slide 25 with respect to the support plate 24. In order to move the belt 27 disposed on the nose 58 into contact with the side wall, the belt frame 26 is adapted to be pivoted with respect to the slide 25. The pivotal action is provided by means of an air cylinder 60 which is attached to post 61 secured to slide 25. The piston rod 62 of the cylinder 60 is attached through link 63 to the inner end portion of the belt frame 26. Air is introduced to opposite ends of the cylinder through lines 64 and 65. By introducing air into the upper end of the cylinder 60 through line 64, the piston rod 62 is extended to pivot the belt frame 26 about stud 52 and bring the belt 27 into engagement with the side wall of the workpiece. Introducing air into the lower end of the cylinder 60 through line 65, will retract the piston rod and move:

' the belt 27 disposed on nose 58 out of contact with the workpiece. The air pressure acting within the cylinder 60 provides a floating action which permits the belt 27' and nose 58 to move or float over irregularities or surface defects in the workpiece. In addition to permitting the; abrading member to move over defects and irregularities, the floating action provided by the air cylinder 69 enables the abrasive member 27 to move or float over small. ridges or steps in the interior surface of the workpiece..

To provide a sunray-type of pattern or finish on the workpiece, the belt 27 is fixed on the nose 58 during the polishing operation. After polishing, it is desirable to move or index the belt to provide a new or clean portion of the belt on the nose. The belt 27 is contained on a reel 66 which is attached to post 61 and the belt, after leaving the reel 66, travels over a roller 67 rotatably secured to bracket 68 attached to the reel. After passing over the roller 67, the belt travels around roller 69 and around the nose 58 to the index rollers 70 and 71. The roller 69 is rotatably secured to the belt frame 26 and is located between the belt frame and slide 25.

The index roller 70 is secured to a hub 72 mounted on a shaft 73 which extends outwardly from the belt frame 26. A ratchet 74 and link 75 are also mounted on the shaft '73. The ratchet is indexed or rotated by means of an indexing pawl 76 which is pivotally connected to the link 75. A spring 77 connects the end of the pawl 76 with the link 75 and serves to bias the pawl into engagement with the teeth of the ratchet 74.

The ratchet 74 is indexed to move the belt 27 by means of an air cylinder '73 connected to a bracket 79 or plate attached to belt frame 26. The piston rod 80 of the air cylinder 78 is connected by a clevis 81 to the top of the link 75. Air is introduced into the cylinder 73 to pivot the link '75 and index the ratchet 74 through an air line 82.

By introducing air into the cylinder through line 82, the link 75 is pivoted to cause the indexing pawl 76 to move the ratchet 74 and roller 70 a given increment and thereby move the belt 27 disposed between the rollers 70 and '71 and present a new polishing surface for the polishing operation.

The ratchet 74 is locked in position by a locking pawl 83 mounted on a shaft 8 extending outwardly from the belt frame 26. The shaft 84- also carries idler roller '71 which is disposed adjacent the index roller 70. The locking pawl 83 is biased into engagement with the teeth of the ratchet 74 by a spring 85.

To limit the pivotal movement of the belt frame 26 by action of cylinder 6%, a bracket 86 is secured to the inner end of slide 25. A pair of studs 87 are threaded within suitable openings in the flanges of the bracket 86 and are disposed in position to be engaged by the end 83 of the belt frame 26 when the belt frame is pivoted. Generally, the outward pivotal movement of the arm 54 is limited by engagement of the nose 58 with the side wall of the workpiece so that the floating action of the air in cylinder 60 can be utilized. It is only at the end of the outward stroke when the nose is brought upwardly around the flared outer end of the workpiece that the end 88 of the frame actually engages the stud 87 to limit. the pivotal movement of the belt frame 26.

To control the inward and outward stroke of the side wall head 13 as well as the pressure of the nose 58 against the side wall, an adjustable control mechanism is employed which actuates limit switch controls. This mechanism includes a pair of brackets 89 which extend upwardly from the slide 25, and each bracket supports a thread stock 911 and 91. The smaller diameter thread stock 91 is threaded within the outer end of the thread stock 9-1? which is of a larger diameter. The outer end of the thread stock 91 is adapted to engage the stop plate 39 and limit the outward movement of the slide 25 and the belt frame 26. The thread stocks 90 and -91 are locked in the desired relative position by means ,of a lock nut 92.

The inner thread stock 91 also carries two adjustable nuts 93 and 94 which are adapted to actuate a limit switch 95 secured to plate 24 on the outward stroke of the slide 25.

The outer thread stock 90 carries a hub 96 and a nut 17 is threaded onto the hub 96 and serves to actuate a limit switch 98 on the inner stroke of the slide 25. The hub 96 is locked in position on the thread stock 911 by means of a lock nut 99 and nut 97 is locked by lock nut 101 In addition to hub 96, a beveled nut 1111 is threaded on the thread stock 91 and locked in place by lock nut 1112. The nut 1111 is adapted to be used in the event the inner surface of the workpiece has a stepped surface, in which case the pressure of cylinder 61) on nose 53 will be released as the nose rides over the step. This position of pressure release can be adjusted by means of the nut 101.

The inward stroke of the slide 25 is limited by the engagement of the rim 1113 of hub 96 with the stop 164 secured to the support plate 24.

By proper adjustment of the nuts 93 and 94, as well as the nuts 97 and 101, the action of the abrasive head 16 can be controlled in any desired sequence.

To slow down the forward stroke of the side wall head and permit the head to dwell in a given area of the side wall for a longer period of time, as in the case where the area may contain a defect or deformity, a hydraulic cam mechanism is employed. The cam mechanism includes a cam follower 1&5 which is connected to support plate 24 and is adapted to be engaged by a suitable cam 106 secured within T-slot 197 formed in the slide 25.

The cam 1% can be provided with any desired length and depth with the length of the cam determining the length of the slow down area and the depth of the cam 1116 determining the rate of speed of the slide in this area. The hydraulic cam mechanism is connected to the hydraulic system operating cylinder 45 and engagement of the follower res by the cam 10'6 actuates a valve 1117a located in the hydraulic line leading to the cylinder 45 to retard the rate of fiow of hydraulic fluid to the cylinder and thereby slow down the rate of travel of the slide 25, resulting in the belt 27 operating on a given area of the side wall for a longer period of time.

If a defect is present in the side wall of the workpiece, all workpieces of the same batch or run usually contain similar defects. In this situation, the hydraulic cam mechanism will automatically move the side wall head more slowly over this defective area and remove more metal. The hydraulic cam mechanism is only employed on the inward stroke of the side wall head, for it is desired that the outward stroke be of a constant speed to provide a uniform finish on the side wall.

The bottom wall head 14, which is adapted to polish the bottom surface of the workpiece, includes a base 168 which is secured to wall 23 of column 10. A pair of horizontal bars 109 are secured in spaced relation to the base 1th; and support the guide support plate 11d which is similar in structure to support plate 24 of the side wall head. Support plate 111 is secured to the bars 1% by bolts 111 and is provided with a pair of guide surfaces 112 and a central longitudinal recess 113 which is adapted to receive an hydraulic cylinder.

A slide 114 is slidably mounted on support plate and is formed with a central guide way 115 which receives the guides 112. An adjustable gib 116 is disposed between the sliding surfaces to take up the wear of the sliding motion. The slide 114 is also formed with a central recess 117 complementing recess 113 in the support plate.

The slide 114 is moved relative to the support plate 111 by means of a piston rod 118 of cylinder 119 which is secured to one end of the slide by means of a plate 1211. A threaded rod 121 is connected by clevis 122 to the rear end of cylinder 119 and extends through an elongated plate 123 by suitable lock nuts. The plate 123 is supported by a pair of support rods 124 which straddle rod 121 and extend outwardly from plate 110.

With this construction, the piston rod 118 is connected to the slide 114, while the cylinder 119 is connected to the support 110. Hydraulic fluid is adapted to be introduced into the opposite ends of the cylinder through lines 125 and 126, respectively. The adjustment provided by rod 121 enables the cylinder to be moved relative to the support member 111) and makes it possible to vary the inward position of the abrasive member with respect to the chuck.

By introducing fluid into the end of the cylinder through line 125, the piston rod will be withdrawn within the cylinder 119 causing the slide 114 to move relative to the support plate 1111 resulting in the abrasive member, carried by the slide 114, being moved from the center of the bottom surface of the workpiece to the periphery. Conversely, if the hydraulic fluid is introduced into the cylinder through line 126, the piston rod is extended to cause the slide 114 and the abrasive member to move 9. center of the workpiece to the periphery and return to the center in order to polish the bottom surface of the workpiece. After closing of the turret 4, the nose 149 will be disposed out of contact with the bottom surface the workpiece and the cylinder 136 is then actuated to move the nose 149 into contact with the bottom surface. The air pressure in the cylinder 136 serves to apply a resilient pressure to the nose 149 and permit the nose to fioat over irregularities or surface defects in the bottom wall of the workpiece.

The cylinder 113 serves to move the slide 114 and the belt frame 127 in relation to the support plate 110 and thereby move the nose from the center of the workpiece to the periphery and subsequently return the nose from the periphery to the center of the workpiece to complete the polishing operation.

The polishing operation is controlled through an electrical system, as shown in FIG. 7. In the electrical control diagram, the main control power lines are indicated by 196' and 191 and the horizontal branch lines connected across the control power lines are designated by an 'L series of numbers, such as L1, L2, etc. The contacts actuated by a given relay are designated by the reference number of the relay and a hyphenated number.

To begin operation, the vertical position of the side wall head 13 is adjusted by turning the threaded shaft 28 which will position the head for any given diameter of workpiece. The angularity of the side wall head 13 is also adjusted to correspond to the angularity of the side wall of the workpiece by loosening nut 37 and pivoting the entire support plate 24 to the desired angle.

In addition, if it is desired to have the side Wall head -13 dwell or 'slow downata givenarea along the side wall, the hydraulic cam mechanism can be inserted into the structure. This requires that the lug 106 be secured within the key slot 107 in slide 25 at the desired position so that the cam follower 105 will contact the lug 106 at the position at which the slow down is desired.

The automatic sequence of the polishing apparatus of the invention is set up by a plurality of toggle switches located on a control panel. These toggle switches are indicated by 192, 193, 194, 195 and 196.

To begin operation, the turret 4 is in the open position and toggle switch 192 in L9 is open, toggle switch 193 in L14 is open, toggle switch 1% in L16 is closed, toggle switch 195 in L11 is closed and toggle switch 196 in L12 is in the up position, as shown in FIG. 7.

De ressing push button 197 in L1 energizes the magnetic motor starter 193 which controls the vacuum pump which is connected to the hollow chuck shaft to hold the workpiece against the chuck. The motor starter 198 could also be employed to control the hydraulic pump for the hydraulic system and to control the pump for the coolant material introduced to the workpiece through the nozzle 1'74. Alternately, three separate motors may be controlled with motor starter 198. Energizing motor starter 198 closes contacts 198-1 in L2 to hold in the motor starter 198.

Depressing the start cycle button 199 in L3 energizes relay 2:70 to close contacts ZiltLl in power line 190 and contacts 209-2 in power line 191. Energizing relay 2% also closes contacts 283%: in L4.

The closing of contacts 2634 and 2002 energizes solenoid 231 in L21 to introduce air through line 19 to cylinder 15 to close the turret 4. As the turret 4 starts to close, limit switch 202 in L4 is released and closed to hold relay 2%.

When the turret 4 is completely closed, limit switch 22 in L5 is engaged and closed by Wall 23 of column 10.

losing of limit switch 2 2 energ zes solenoid 293 in L5 to actuate hydraulic motor 9. In addition, the closing of limit switch 22 also energizes solenoid 204 in L6 to open a valve in the coolant line and permit the coolant to he introduced through nozzle 174 to the workpiece. Furthermore, the closing of limit switch 22 actuates .of the workpiece.

solenoid 2% in L7 resulting in hydraulic fluid being introduced through line 49 to cylinder 45 to move the slide 25 inwardly toward the workpiece. The energizing of solenoid 205 also results in hydraulic fluid being introduced through line into cylinder 118 to move the slide 114 in relation to support plate 116 and move the abrasive belt 145 from the center of the bottom surface of the workpiece toward the periphery thereof.

As the slide 25 begins its movement, nut 94 moves out of contact with limit switch 95 in L11 which then closes, and similarly, as the slide 114 begins its movement, nut 182 on thread stock moves out of contact with limit switch 183 in L15 causing limit switch 183 to close. Closing of limit switch 95 in L11 and 183 in L15 energizes solenoids 296 in L11 and 297 in L15, respectively. The energizing of solenoid 206 results in air being introduced through line 64 to cylinder 69 to pivot the belt frame 26 and bias the nose 58 into engagement with the side wall Similarly, energizing solenoid 207 causes air to be introduced through line 139 to cylinder 136 to bias the nose 149 into engagement with the bottom surface of the workpiece. At this time, the side wall head 13 is moving inwardly from the periphery of the workpiece to the bottom and the air pressure within cylinder 6t) biases the abrasive member into engagement with the side wall. Simultaneously, with this action, the bottom wall head is moving from the center of the workpiece toward the periphery and the air pressure within cylinder 136 biases the abrasive member 145 into contact with the bottom surface of the workpiece.

Assuming that the slide 25 of the side wall head 13 reaches its innermost position before the slide 114 of the bottom wall head reaches its terminal position at the periphery of the bottom wall, limit switch 98 in L11 is actuated by nut 97 on thread stock 99 causing the limit switch 93 to open. Opening of limit switch 98 de-energizes solenoid 266 to release the nose pressure against the side wall of the workpiece.

When the slide 114 of the bottom wall head reaches its end point of travel, limit switch 137 in L15 is actuated by nut to open limit switch 137 and tie-energize solenoid 297. This releases the air pressure of cylinder 136 and moves the abrasive member out of contact with the bottom surface of the workpiece. The closing of limit switch 187a in L17 which is in series with the normally open limit switch 98a (now closed) energizes relay in L18. Energizing relay closes contacts 2384 in LII-3 to hold in the relay 2&3. The energizing of relay 258 also closes contacts 238-2 in L16 to energize the solenoid through the closed toggle switch 194, the closed limit switch 1-33 and the closed toggle switch a. Energizing solenoid 237 restores the contact pressure of the bottom wall head 14 and biases the abrasive belt 145 into engagement with the bottom surface of the workpiece.

In addition, contacts 2533-3 in L12 are closed, resulting in solenoid 2% in L11 being energized through the switch 196 being in the upper position and the limit switch 95 being closed and toggle switch 195 being closet. Energizing solenoid 236 restores the contact pressure to the side wall head and biases the nose 53 into engagement with the side wall of the workpiece. It is to be noted that the contact pressure applied to the abrasive members is restored before return travel of the side wall head and bottom wall head is started.

Energizing of relay 268 in Lid also closes contacts 25384 in L8 to energize solenoid 299 which reverses the how of hydraulic fluid to cylinder 5 moves the side wall head 13 outwardly toward the side wall of the workpiece. The energizing of solenoid 2 39 also reverses the flow of hydraulic fluid to cylinder 119 to cause the bottom wall head to move from the periphery of the bottom surface of the workpiece toward the center thereof.

The energizing of relay 2% also opens contacts 2ii85 I 1 in L7 to prevent the slides iron-1 moving in the origins direction and also closes contacts Zed-6 in L18.

When the side wall head 13 reaches its outermost position in the outward stroke of travel, limit switch 95 in L11 is actuated and opened to de-energize solenoid 266 and release the nose pressure. Similarly, when the bottom wall head 14 reaches the center position, limit switch 133 in L15 is actuated and opened to de-cnergize solenoid 207 and release the pressure of the abrasive member against the bottom surface. The closing of limit switch 183a in L18 in series with limit switch 950, which closed first on the side wall head reaching its outermost position, and in series with the closed contacts 203-6 energizes relay 210 in L18.

Energizing relay 210 opens the normally closed contacts 210-1 in L5 to tie-energize solenoids 203 and 204 to stop the rotation of the chuck and the coolant spray. In addition, the energizing of relay 210 closes contact 210-2 in L20 to energize solenoid 211 and thereby introduce air under pressure through line 18 to cylinder 15 and pivot the turret 4 to the open position to permit the workpiece to be removed from the chuck and a second workpiece to be inserted within the chuck. The contacts 210-1 in L5 provide a means for a fast stoppage of chuck rotation before the turret 4 is opened.

The energizing of relay 210 also opens contacts 210-3 in L21 to prevent the turret from closing.

As the turret 4 pivots or opens, limit switch 2&2 in L4 opens to release relay 200 in L3 and relay 208 in L10.

The release of relay 200 de-energizes the circuit and the release of relay 208 sets up the circuits for the next cycle. At the start of the cycle, relay 208 is de-energized so even though limit switches 95a and 1830 in L18 are closed, relay 210 is not energized because contacts 293-6 in L18 are open.

Due to the above circuitry, either slide 25 or 114 on reaching the end of its stroke will dwell before reversal because limit switch 98a and 187a are in series in L17. Therefore, both of the switches 98a and 187a must be closed to start the return stroke.

The manual stop button 212 is employed in L1 to stop the action of the vacuum, hydraulic and coolant pumps and a similar stop cycle button 213 is employed in L3 to stop the entire automatic cycle, if desired.

With the above circuitry, the contact pressure of the side wall head against the side wall of the workpiece is restored instantly on the start of the outward stroke.

The above description was directed to a single cycle of operation and if it is desired to repeat the cycle, the toggle switch 192 in L9 is closed. The circuitry remains the same, but as start cycle button 199 in L3 is depressed and relay 200 is energized to close contacts 201-1 and 202-2 in the main power lines, the timer motor 214 in L9 is energized to drive the recycling timer.

At the end of one cycle, limit switches 95 and 183 in L11 and L15, respectively, are opened with the relay 203 in L10 still energized. With the toggle switch 1920 in L19 closed and limit switches 95:: in L1? and 133a i L18 closed, relay 215 in L19 is energized through timer contacts 216 which are closed at this time. Energizing relay 215 opens contacts 215-1 in L10 which are in series with maintaining contacts 208-1. Normally closed contacts 215-1 are opened to release relay 208 and reverse the travel of slides 25 and 114. Relay 210 in L18 was not energized at this time due to the timer contacts 217 being open.

If the timer completes its timing cycle before the next cycle or reciprocation of the slides, contacts 217 in L18 will close and contacts 216 in L19 will open. Then as the slides actuate the limit switches 95 and 183, relay 215 in L19 will not be energized but relay 210 in L18 will energize to open the turret by energizing solenoid 211 in L20. As in the case of the single cycle, the opening of the 12 turret opens limit switch 202 to release relay 200 which de-energizes the circuit.

In some cases, the outer edge of the side walls of the workpiece may flare outwardly. In this case, it is desirable to have the contact pressure of the side wall head maintained during the entire outward stroke of the head so that the abrasive member will engage or wipe along the flared outer edge of the workpiece. To set up the circuitry for a situation such as this, toggle switch 196 on the control panel is thrown to the lower position, as shown in FIG. 7. Therefore, the limit switch 95, which is adapted to open when the side 25 reaches the end of its stroke of travel, is shunted through line 13 due to the toggle switch 196 being in the lower position so that the nose or contact pressure actuated by solenoid 206 will remain on at the end of the outward stroke of travel of the side wall head.

Another variation of the cycle can be obtained by closing toggle switch 193 on the control panel, and having toggle switch 196 in the down position. In this situation, the relay 218 in L14 is energized to thereby close the normally opened contacts 218-1 in L12 and open the normally closed contacts 218-2 in L12. As contacts 213-2 in L12 are open, limit switch 98 in L11 is reset or closed before solenoid 205 is energized to supply contact pressure to the abrasive belt 27. Closing of contacts 218-1 in L12 shunts limit switch to keep contact pressure on the abrasive belt at the end of the outward stroke.

Another variation of the polishing action of the side wall head, toggle switch 193 in L14 is opened and toggle switch 196 is in the center position, as shown in FIG. 7. As toggle switch 193 is opened, relay 218 will not be energized so neither the toggle switch 196 or the contacts 218-1 will shunt the limit switch 95. Therefore, the contact pressure on the abrasive belt 27 is under the control of both the limit switches 95 and 98 and the contact pressure on the abrasive belt will be released as the limit switches are actuated.

The toggle switch 194 in L16 serves to control the contact pressure on the bottom wall head 14. If the switch is in the closed position, the contact pressure on the belt of the bottom wall head 14 will be established instantly at the start of the inward stroke. However, if the toggle switch 194 is opened in L16, the limit switch 187 in L15 will control the pressure of the belt 145 and will energize solenoid 207 when the switch 187 is reset or closed.

The toggle switch 195 in L11 and 195a in L15 are connected in series with solenoids 206 and 207, respectively, which control the contact pressure on the abrasive members. When the switches 195 and 195a are in the open position, the solenoids 206 and 207 will not be energized and there will be no contact pressure on the abrasive members to bias the same into contact with the surfaces of the workpiece.

While the above description is directed to the use of a stationary belt or abrasive member to be employed in the polishing operations, it is contemplated that if other types of finishes are desired on the workpiece, a moving belt or other types of abrasive members may be employed and controlled in the same manner. Similarly, the above description is directed to polishing the interior surfaces of a workpiece, but it is contemplated that the exterior surfaces of the workpiece can be polished, abraded or otherwise finished in a like manner, if desired.

The present invention provides an apparatus for simultaneously polishing the bottom and side wall surfaces of a workpiece in a continuous operation. Any one of a number of automatic cycles can be set into the apparatus to bring about any desired type of polishing action for a given workpiece. By using the timer in the electrical system, the operations can be repeated for any desired number of cycles without the turret opening. The automatic polishing operation is conveniently set up for any 13' workpiece by merely actuating the toggle switches on a control panel.

By means of the air pressure, a floating action is provided for the abrasive members against the surfaces of the workpiece. This permits the apparatus to ride over surface irregularities or defects and polish out-of-round and deformed containers.

The provision is also made in the present apparatus for permitting the side wall head to slow down or dwell at a given area along the side wall of the workpiece to provide a more complete grinding or polishing of this area.

To provide the sunray-type of finish, a stationary abrasive member is employed and a provision is made for automatically indexing the belt at the completion of the polishing operation to provide a new or clean abrasive surface for the next cycle.

Various modes of carrying out the invention are contemplated as being within the scope of the following claims particularly pointing out and distinctly claiming the subject matter which is regarded as the invention.

I cl im:

1. An apparatus for polishing a workpiece having a bottom surface and side walls extending outwardly from said bottom surface, comprising a frame, a chuck mounted on the frame and adapted to support the workpiece, means for rotating the chuck about the axis thereof, a turret pivotally connected to the frame and adapted to be moved from an open to a closed position, a pair of polishing heads supported by the turret with the first of said heads having an abrasive member disposed to polish the side wall surfaces of the workpiece and the second of said heads having a second abrasive member disposed to polish the bottom surface of the workpiece when the turret is in the closed position, drive means for moving said first head relatively with respect to the turret to thereby move the abrasive member along the side wall of the workpiece, second drive means independent from said first drive means for moving the second head with respect to the turret to thereby move the second abrasive member along the bottom surface of the workpiece to polish the same, means for biasing said first abrasive member into contact with the side wall of the workpiece, and means for biasing the second abrasive member into contact with the bottom wall of the workpiece.

2. The structure of claim 1 in which the polishing heads include a belt frame, a contact member supported by the belt frame and disposed to engage the surface of the workpiece, an abrasive belt mounted on the belt frame and extending over said contact member, and means for indexing the belt after a polishing operation to move the belt over the contact member and present a new belt surface on said contact member.

3. An apparatus for polishing a workpiece having a bottom surface and side walls extending outwardly from said bottom surface, comprising a frame, a chuck mounted on the frame and adapted to support the workpiece, means for rotating the chuck about the axis thereof, a turret pivotally connected about a vertical axis to the frame, a pair of polishing heads supported by the turret with the first of said heads having an abrasive member adapted to polish the side walls of the workpiece and the second of said heads having a second abrasive member adapted to polish the bottom surface of the workpiece, pivotal means for pivoting the turret with respect to the frame to move the heads toward the chuck into polishing position and to move the heads away from the chuck to permit insertion and removal of the workpiece from the chuck, and drive means for moving said heads with respect to the turret to thereby move the first abrasive member along the side wall of the wor :piece to polish the same and to move the second abrasive member along the bottom surface of the workpiece to polish the same.

4. In an apparatus for polishing tne surface of a workpiece, a frame, a chuck supported by the frame and adapted to carry the workpiece to be polished, a polishing head connected to the frame and having an abrasive mem ber disposed to contact the surface of the workpiece, drive means for providing relative movement between the chuck and said abrasive member to thereby polish the surface of the workpiece, and means connected to said drive means for modifying the relative movement between said chuck and said abrasive member at a given period during said movement to provide a more concentrated polishing action on said surface during said period.

5. In an apparatus for polishing the surface of a workpiece, a frame, a chuck supported by the frame and adapted to carry the workpiece to be polished, a polishing head connected to the frame and having an abrasive member disposed to contact the surface of the workpiece, drive means for moving said abrasive member relative to said chuck in a given stroke to move the abrasive member along the surface of the workpiece to polish the same, and means connected to said drive means for retarding the speed of movement of said abrasive member during a given portion of said stroke to thereby provide a more concentrated polishing action on said surface during said portion of the stroke.

6. In an apparatus for polishing the surface of a workpiece, a frame, a chuck supported by the frame and adapted to carry the workpiece to be polished, a polishing head connected to the frame and having an abrasive member disposed to contact the surface of the workpiece, drive means for reciprocating said abrasive member relative to said chuck in a forward and return stroke to thereby move the abrasive member along the surface of the workpiece to polish the same, and means connected to the drive means for retarding the speed of movement of said abrasive member along. agiven length. ofsaid forward stroke to thereby provide a more concentrated polishing action on said surface along said length and for maintaining a constant speed of movement of said abrasive member during said return stroke.

7. In an apparatus for polishing the surface of a workpiece, a frame, a chuck supported by the frame and adapted to carry the workpiece to be polished, means for rotating the chuck about the axis thereof, a polishing head connected to the frame and having an abrasive rnember disposed to contact the surface of the workpiece, hydraulically. actuated drive means for reciprocating said abrasive member relative to said chuck in a fonward and return stroke to thereby move the abrasive member along the surface of the workpiece to polish the same, hydraulic supply means connected to said drive means for supplying hydraulic fluid to said drive means to operate the same, and means connected to said supply means for varying the supply of fluid to said drive means to retard the speed of movement of said abrasive member along a given length of said forward stroke and thereby provide a more concentrated polishing action along said length and to maintain a constant speed of movement of said abrasive member during said return stroke.

8. An apparatus for polishing a workpiece having a bottom surface and side walls extending outwardly from said bottom surface, comprising a frame, a chuck mounted on the frame with the axis of said chuck being in a horizontal plane and adapted to support the workpiece, means for rotating the chuck about the axis thereof, a turret pivotally connected about avertical axis to the frame, a pair of polishing heads supported by the turret with the first of said heads having an abrasive member adapted to polish the side walls of the workpiece and the second of said heads having a second abrasive member adapted to polish the bottom surface of the workpiece, pivotal means for pivoting the turret with respect to the frame to move the heads toward the chuck into polishing position and to move the heads away from the chuck to permit insertion and removal of the workpiece from the chuck, drive means for moving said heads with respect to the turret to thereby more the first abrasive member along the side wall of the workpiece to polish the same and to move the second abrasive member along the bottom surface of the workpiece to polish the same, and means acting simultaneously with said drive means for introducing a coolant to said workpiece with the excess coolant being free to drain from said workpiece due to the axis of said chuck and workpiece being in a horizontal plane.

9. An apparatus for polishing a workpiece having a bottom surface and a side wall, comprising a frame, a chuck supported by the frame and adapted to carry the workpiece to be polished, chuck drive means to rotate the chuck about the axis thereof, a turret connected to the frame, a pair of polishing heads supported by the turret with one of said heads being a bottom wall polishing head and having an abrasive member adapted to polish the bottom wall of the workpiece and the other of said heads being a side wall head having an abrasive member adapted to polish the side wall of the workpiece, turret drive means for moving the turret to a closed position to bring the polishing heads into polishing position and for moving the turret to an open position to permit insertion and removal of the workpiece from said chuck, head drive means for moving the side wall polishing head relative to said turret to thereby move the corresponding abrasive member along the side wall of the workpiece and for moving the bottom wall head relative to said turret to thereby move the corresponding abrasive member along the bottom wall of the workpiece, fluid pressure means for independently urging the abrasive members into contact with the bottom wall and side wall of the workpiece, respectively, means responsive to the movement of the turret to the closed position for actuating said drive means to move the abrasive members alongthe workpiece, means responsive to the initial movement of the heads for actuating said fluid pressure means to thereby urge said abrasive members into contact with the respective surfaces of the workpieces, and means responsive to the polishing heads completing a given length of movement for releasing said fluid pressure means and moving said abrasive members out of contact with the workpiece.

10. An apparatus for polishing the surface of a workpiece having a bottom surface and a side wall, comprising a frame, a chuck supported on the frame and adapted to carry the workpiece to be polished, chuck drive means for rotating the chuck about the axis thereof, a turret connected to the frame, a pair of polishing heads supported by the turret with one of said heads being a side wall polishing head adapted to polish the side wall of the workpiece and the other of said heads being -a bottom wall head adapted to polish the bottom wall of the workpiece, an abrasive member carried by each of said polishing heads, said abrasive members adapted to contact and polish the bottom wall and side wall of the workpiece,

respectively, turret drive means for moving the turret to a closed position to bring the abrasive members into a polishing position and for moving said turret to an open position to permit insertion and removal of the workpiece :from said chuck, said drive means for reciprocating the :side wall polishing head relative to said turret to thereby :move the corresponding abrasive member along the side wall of the workpiece to polish the same and for reciprocating the bottom wall head relative to said turret to -thereby move the corresponding abrasive member along the bottom wall of the workpiece to polish the same, fluid pressure means for independently urging each of the abrasive members into con-tact with the respective surface of the workpiece, means responsive to movement of the turret to the closed position for actuating the head drive means to move the heads in a forward stroke of travel, means responsive to initial movement of the heads in the forward stroke for actuating said fluid pressure means to urge the abrasive members into contact with the workpiece, means responsive to a given amount of movement of said heads in said forward stroke for stopping said forward strokes, means responsive to the heads completing the respective forward strokes of travel for releasing said fluid pressure means and moving the abrasive members out of contact with the workpiece, means responsive to both of said heads completing the forward stroke of travel for actuating said fluid pressure means and urging said abrasive members into contact with the workpiece for the return stroke of travel, means responsive to the actuation of said fluid pressure means for actuating said head drive means to move the heads in the return stroke of travel, and means responsive to the heads reaching the end of the return stroke of travel for stopping said head drive means and said fluid pressure means and for actuating said turret drive means to move the turret to the open position.

11. An apparatus for polishing the surface of a workpiece having a bottom surface and a side wall, comprising a frame, a chuck supported on the frame and adapted to carry the workpiece to be polished, chuck drive means for rotating the chuck about the axis thereof, a torrent connected to the frame, a pair of polishing heads supported by the turret with one or" said heads being a side wall polishing head adapted to polish the side wall of the workpiece and the other of said heads being a bottom wall head adapted to polish the bottom wall of the workpiece, an abrasive member carried by each of said polishing heads, said abrasive members adapted to contact and polish the bottom wall and side wall of the workpiece, respectively, turret drive means for moving the turret to a closed position to bring the abrasive members into a polishing position and for moving said turret to an open position to permit insertion and removal of the workpiece from said chuck, said drive means for reciprocating the side wall polishing head relative to said turret to thereby move the corresponding abrasive member along the side wall of the workpiece to polish the same and for reicproeating the bottom wall head relative to said turret to thereby move the corresponding abrasive member along the bottom wall of the workpiece to polish the same,

fluid pressure means for independently urging each of the abrasive members into contact with the respective surface of the workpiece, means responsive to movement of the turret to the closed position for actuating the head drive means to move the heads in a forward stroke of travel, means responsive to initial movement of the heads in the forward stroke for actuating said fluid pressure means to urge the abrasive members into contact with the workpiece, means responsive to a given amount of movement of said heads in said forward stroke for stopping said forward strokes, means responsive to the heads completing the respective forward strokes of travel for releasing said fluid pressure means and moving the abrasive members out of contact with the workpiece, means responsive to both of said heads completing the forward stroke of travel for actuating said fluid pressure means and urging said abrasive members into contact with the workpiece for the return stroke of travel, means responsive to the actuation of said fluid pressure means for actuating said head drive means to move the heads in the return stroke of travel, and means for stopping the chuck drive means prior to actuating said turret drive means to thereby stop rotation of the chuck before the turret is moved to the open position.

12. An apparatus for polishing a workpiece having a bottom surface and side walls extending outwardly from said bottom surface, comprising a frame, a chuck mounted on the frame and adapted to support the workpiece, means for rotating the chuck about the axis thereof, a turret pivotally connected to the frame about a vertical axis, means for pivoting said turret from an open to a closed position, a belt support member connected to the turret, a contact member carried by the belt support member, an abrasive belt mounted on the belt support member and disposed over the contact member with the portion of the belt located on said contact member being fixed during the polishing operation and disposed to contact the workpiece to polish the same when the turret is in the closed position, means for indexing the belt on the contact member after the polishing operation to provide a clean portion of the belt on said contact member, means for supplying a cooling liquid to the location of the contact member to cool the portion of the belt thereon during the polishing operation, a hood secured to the frame, and a second hood mounted on the turret and cooperable with the first hood to provide an enclosure for the chuck and contact member when the turret is in the closed position and prevent splattering of the cooling liquid.

13. In a polishing apparatus, a polishing head comprising a support member, a slide slidably mounted on said support member, a belt frame pivotally connected to the slide, a contact member connected to the belt frame, an abrasive belt supported by the belt frame and disposed over the contact member with the portion of the belt located on said contact member being adapted to contact the workpiece and polish the same, means for moving the slide relatively of the support member to move the contact member along the workpiece, first fluid pressure means separate from said last named means and responsive to initial movement of said slide and operably connected to the belt frame for urging the belt frame radially outward to thereby bias the contact member into engagement with the workpiece, and second fluid pressure means responsive to the contact member reaching the end of the polishing stroke and operably connected to the belt frame for pivoting the belt frame radially inward to move the contact member out of engagement with the workpiece at the end of the polishing stroke.

14. The structure of claim 13 and including adjustable means for adjustably limiting both the inward and outward movement of the belt frame.

References Cited in the file of this patent UNITED STATES PATENTS 446,170 Sperry Feb. 10, 1891 1,993,543 Egger Mar. 5, 1935 2,424,835 Luckey et al July 29, 1947 2,445,391 Elmes et a1. July 20, 1948 2,558,300 Knapp June 26, 1951 2,573,220 Riedesel et al Oct. 30, 1951 2,620,602 Schenk Dec. 9, 1952 2,736,148 Thacher Feb. 28, 1956 2,798,340 Roberts July 9, 1957 2,828,586 List et al Apr. 1, 1-958 

3. AN APPARATUS FOR POLISHING A WORKPIECE HAVING A BOTTOM SURFACE AND SIDE WALLS EXTENDING OUTWARDLY FROM SAID BOTTOM SURFACE, COMPRISING A FRAME, A CHUCK MOUNTED ON THE FRAME AND ADAPTED TO SUPPORT THE WORKPIECE, MEANS FOR ROTATING THE CHUCK ABOUT THE AXIS THEREOF, A TURRET PIVOTALLY CONNECTED ABOUT A VERTICAL AXIS TO THE FRAME, A PAIR OF POLISHING HEADS SUPPORTED BY THE TURRET WITH THE FIRST OF SAID HEADS HAVING AN ABRASIVE MEMBER ADAPTED TO POLISH THE SIDE WALLS OF THE WORKPIECE AND THE SECOND OF SAID HEADS HAVING A SECOND ABRASIVE MEMBER ADAPTED TO POLISH THE BOTTOM SURFACE OF THE WORKPIECE, PIVOTAL MEANS FOR PIVOTING THE TURRET WITH RESPECT TO THE FRAME TO MOVE THE HEADS TOWARD THE CHUCK INTO POLISHING POSITION AND TO MOVE THE HEADS AWAY FROM THE CHUCK TO PERMIT INSERTION AND REMOVAL OF THE WORKPIECE FROM THE CHUCK, AND DRIVE MEANS FOR MOVING SAID HEADS WITH RESPECT TO THE TURRET TO THEREBY MOVE THE FIRST ABRASIVE MEMBER ALONG THE SIDE THE SECOND ABRASIVE MEMBER ALONG THE BOTTOM SURFACE OF THE WORKPIECE TO POLISH THE SAME. 